| Description |
The transition from the High Resolution Fly's Eye (HiRes) experiment to the Telescope Array (TA) experiment has been completed. The TA Middle Drum fluorescence detector was built using refurbished telescopes from the HiRes-1 site so that a direct comparison could be made between the energy scales of the two experiments. I have made a comparison between the published HiRes spectrum [3] and a preliminary energy spectrum using data collected with the Middle Drum telescopes. Both sets of data represent measurements made via the monocular observation technique and were analyzed using the HiRes-1 profile-constrained geometry reconstruction technique. The HiRes-1 data represents almost nine years of exposure and was collected betweenMay 29, 1997 and May 26, 2006. The Middle Drum data were collected over a three-year period between December 16, 2007 and December 16, 2010. The Middle Drum exposure is about one third of the HiRes-1 total exposure. I have demonstrated that the Middle Drum detector has the same energy scale as HiRes-1. The published HiRes-1 and Middle Drum spectra presented in this dissertation were measured using average calibrations. A study was preformed on the HiRes-1 data to determine the systematic effects of using the nightly atmospheric and electronic-calibration databases instead of average values. The difference between using the average values and using the detailed nightly databases was less than 1%, indicating the spectral results are robust to these differences. Finally, a search was made for the interaction between cosmic rays and ions in the heliosphere. This interaction could result in a unique signature of parallel, simultaneous photon showers. The HiRes-1 data were chosen for this search due to its large exposure and resulting data set. Unfortunately, detector limitations restricted the potential observations. No double-shower events were detected; however, if observed, this would be suggestive of new physics. Monte Carlo simulated events were used to calculate a preliminary aperture of the HiRes-1 detector for these exotic events and future refinements will allow us to set a physical limit on the rate of events. I would like to dedicate this work to my wife, Larissa. Your support through this process has been the island in my stream. I would also like to dedicate this work to my son, Evan, and soon-to-be daughter, Shaye, who came at just the right time to keep me smiling. |
